A variety of different crushers have evolved suitable for processing stone, minerals and both domestic and industrial waste including construction materials to generate smaller particulate material and aggregate for subsequent use, processing or disposal. Conventional crushers include gyratory, impact, vibration and jaw crushers. Typically, the crusher is provided with a hopper for receiving the bulk material and a discharge conveyor to transfer the processed and crushed material to a discharge location.
Crushers may be categorised further into stationary crushers designed for large static installations that are assembled on site e.g., at a quarry or mine where they remain until the source of raw material is exhausted. There is also substantial demand for static crushers that are readily transportable from one site to another, for example on a low loader. A second category of crusher is regarded as mobile and typically comprises endless tracks mounted at an undercarriage which is in turn supported by a mainframe (or chassis) of the mobile unit. The chassis further supports the particular type of crusher mounted such as a jaw crusher and the primary motor used to drive both the crusher and the ground engaging tracks.
Conventionally, the primary motor provides drive of the crusher via a belt drive assembly in which a belt is mounted about a pair of pulleys connected respectively to a crusher drive shaft and a drive shaft at the motor (typically a diesel engine). The engine transfers drive to the crusher via a clutch that is engaged during crusher start-up and when the crusher stops or is jammed either by an uncrushable object or by choking. To protect the clutch and the primary motor in these situations, it is known to employ a secondary assistance motor.
JP 2012-96180 discloses a crusher drivable by an engine via a clutch and a secondary hydraulic motor where the two drives may be alternatively engaged for operation of the crusher to improve fuel consumption. UA-7189 discloses a jaw crusher drivably coupled to a main engine and a secondary electric motor via a common drive transmission extending around a drive pulley and a flywheel of the crusher. The motors may be drivably switched when starting the crusher to improve power consumption.
However, conventional multi-drive transmission arrangements are not optimised to provide a compact installation at the crusher unit and/or require additional components to transfer drive to the crusher via a single drive transmission. Accordingly, what is required is a crusher unit that addresses these problems.